You're generating the prompt and pasting it into Bing, which is apparently something that ChatGPT is fine with. The in-app integration of Dall-E straight up refuses to do many things, ranging from generating likenesses of celebrities, characters and now even certain animals for some stupid reason. Microsoft's Bing lets you do more, but not anything \ everything.
I'm just glad I have my local Stable Diffusion which does let me do anything, but it does need planning and work. I just the online AIs when I don't have anything specific in mind, or when my creativity is running low, so it's frustrating when you can't even "imagine" up an interesting picture of an animal.